topdown/units_parse: Avoid extra decimal places for integers. (#5011)

This commit cleans up the output of `units.parse` for integer values. Previously, all values from `units.parse` had their precision set to 10 places past the decimal point, regardless of whether that much precision was actually needed. This commit removes the extra decimal places for integers, giving cleaner outputs.

Signed-off-by: Philip Conrad <philipaconrad@gmail.com>

test/cases/testdata/units/test-units-precision.yaml

@@ -0,0 +1,13 @@
+---
+cases:
+  - data:
+    modules:
+      - |
+        package test
+        p {
+            json.marshal(units.parse("1G")) == json.marshal(1000000000)
+        }
+    note: units_parse/no decimal places for integers
+    query: data.test.p = x
+    want_result:
+      - x: true

topdown/parse_units.go

@@ -108,6 +108,11 @@ func builtinUnits(_ BuiltinContext, operands []*ast.Term, iter func(*ast.Term) e
 
 	numRat.Mul(numRat, &x)
 
+	// Cleaner printout when we have a pure integer value.
+	if numRat.IsInt() {
+		return iter(ast.NumberTerm(json.Number(numRat.Num().String())))
+	}
+
 	// When using just big.Float, we had floating-point precision
 	// issues because quantities like 0.001 are not exactly representable.
 	// Rationals (such as big.Rat) do not suffer this problem, but are